Immatics highlights anti-tumor activity of anzu-cel PRAME cell therapy

Immatics (IMTX) announced the presentation of updated data from 16 patients with metastatic uveal melanoma treated with anzu-cel PRAME cell therapy. The uveal melanoma data from the ongoing Phase 1b trial will be presented today at the European Society for Medical Oncology Congress 2025 during the Presidential Symposium III by Sapna Patel, M.D., Professor of Medicine, University of Colorado Cancer Center. As of September 24, 2025, 16 patients with metastatic uveal melanoma were administered a one-time infusion of anzu-cel at the recommended Phase 2 dose as part of the anzu-cel Phase 1b dose expansion. Patients received a median infused TCR T-cell dose of ~4 billion and had a median of 2 lines of prior systemic treatments. Patients had a median target lesion sum of a diameter of 103 mm, and 81% of patients had liver and extrahepatic metastasis. Anti-tumor Activity and Durability: Continued strong anti-tumor activity and durability of anzu-cel PRAME cell therapy Updated data of a one-time infusion of anzu-cel PRAME cell therapy demonstrated promising benefit in a difficult-to-treat population with limited effective treatment options: Confirmed objective response rate of 67%; Disease control rate of 88%; Median duration of response of 11 months; Median progression-free survival of 8.5 months at a mFU of 10.4 months. The PFS rate was 69% at six months and 39% at 12 months Median overall survival not reached at a mFU of 14.3 months. The OS rate was 71% at 12 months Anti-tumor activity was observed in liver and extrahepatic metastases, including lung, lymph node, abdomen/peritoneum and others. 14/16 patients had target lesions in the liver and treatment with anzu-cel led to a median shrinkage in liver target lesion size of 49.6%. Notably, 11 out of the 16 patients received a TCR bispecific as prior systemic treatment line, and thereof, six achieved a confirmed partial response, one a partial response and three stable disease. These results demonstrate anti-tumor activity of anzu-cel in patients who received prior TCR-based therapies. The most frequent treatment-emergent adverse events were anticipated cytopenias associated with lymphodepletion. Expected and manageable cytokine release syndrome was mostly Grade 1 or 2, which is consistent with the mechanism of action. No patients experienced long-term CRS, and most CRS was resolved by day 14. No anzu-cel-related Grade 5 events were observed. Tolerability in the uveal melanoma subset was generally consistent with the full anzu-cel tolerability profile in the Phase 1b.